The heavyweight fight between Sonny Bill Williams and veteran South African boxer Francois Botha has been rescheduled for February after Williams underwent surgery on a chest muscle injury.

South African promoter World Sport Promotions said an exact date would be worked out after it meets with Australian broadcaster Fox Sports.

The fight is due to take place in Australia.

''We wish Williams a speedy recovery and hope that he is able to return to training soon,'' said Thinus Strydom of WSP.

Williams, the New Zealand heavyweight champion and a dual rugby league and union international, was due to fight Botha in Brisbane on November 24.

Williams tweeted from Australia on Wednesday that the operation on the pectoral muscle he tore playing for his rugby club in Japan this weekend was a success.

The 27-year-old Williams was a member of the All Blacks' World Cup-winning squad last year.

Over the last few years he also has negotiated with his rugby employers to allow him to pursue a boxing career and beat New Zealand-based American Clarence Tillman III on a first-round TKO to win the vacant New Zealand heavyweight belt this February.

Williams has a 5-0 record with three knockouts but the bout with Botha, 44, will likely be his biggest boxing test.

Nicknamed the ''White Buffalo,'' Botha is a former world heavyweight title contender, losing to Lennox Lewis, Wladimir Klitschko, Evander Holyfield and, most recently, Michael Grant.

He also fought Mike Tyson and was stopped in the fifth round after being ahead on points. Botha told South African media this year he was so confident of beating Williams he was willing to fight him ''somewhere during halftime of a rugby match'' and with ''one hand tied behind his back.''

Williams is reportedly being paid $1.2 million to play 12 games for Japan's Panasonic Wild Knights before an expected return to rugby league in Australia's NRL in 2013.